Arp head bolts vs arp head studs
#41
Studs are always better, especially in an aluminum block because:
-Studs are fully threaded to the bottom of the thread bore. With bolts, you're using fewer threads.
-Studs do not turn within the block threads reducing the chance of damaging them. This is less important in an iron block.
-With studs, there's no worry of hydraulically fracturing the block.
-With studs, the nutted end has fine threads making the clamping force of torquing them more accurate.
Studs are easy to install. They have a Allen hex recess on the top end allowing them to spin in easily.
12 point nuts are more "convenient" to use as you can use a smaller socket and it's better locked into it.
ARP bolts are a good step up from stock bolts but studs are the better bet.
-Studs are fully threaded to the bottom of the thread bore. With bolts, you're using fewer threads.
-Studs do not turn within the block threads reducing the chance of damaging them. This is less important in an iron block.
-With studs, there's no worry of hydraulically fracturing the block.
-With studs, the nutted end has fine threads making the clamping force of torquing them more accurate.
Studs are easy to install. They have a Allen hex recess on the top end allowing them to spin in easily.
12 point nuts are more "convenient" to use as you can use a smaller socket and it's better locked into it.
ARP bolts are a good step up from stock bolts but studs are the better bet.
I prefer 12-Point nuts to reduce any rounding off of the nut head.
The biggest thing, in my opinion for studs, is as you said the studs do not turn in the block as you are torquing them down reducing wear and tear on the block threads, especially when used in an aluminum block.
#42
This, and the fact that studs have full thread engagement. Like the other guy said, studs are fully threaded in the block pretty much to the bottom thread. Bolts can't do this in order to prevent the bolt from bottoming out in the hole while tightening. A shorter than ideal bolt must therefore be used. So not only are studs gentler on threads due to a lack of twisting under a load. They are also gentler because they spread the load across MORE threads than bolts.